Ericsson's Regenerator

Source : From the New York Evening Post
Title: Ericsson's Regenerator
Date: Thursday, January 13, 1853.

We gave yesterday as correct an outline as we well could, without diagrams, of the structure of the machinery by which the “Ericsson” is propelled, and the constitution and function of the “Regenerator,” which is the repository of its accumulated vital forces. We showed how, by the operation of this little machine, only ten per cent. on every 300° of heat was wasted, and that in consequence additional heat, after the engine was put in motion, was only required to repair this inconsiderable waste.

We will now describe the heating apparatus.

Under each working cylinder are two furnaces, each about the size of, if anything smaller than, the interior of an ordinary country house-oven, in which is kept up a moderate fire with anthracite coal.

The distance between the upper surface of the coals and the fire surface of the cylinder is so great—between four and five feet—that the heat from the coals only acts by way of radiation, there being no blaze, and the bottom of the cylinder being entirely removed from any direct contact with the fire.

The ordinary consumption of the four furnaces in the “Ericsson” is six tons in twenty-four hours. They cannot consume over seven tons within that period. They use no blowers, nor any other artificial auxiliaries of combustion; nor, at the highest rate of speed, will the coal burn materially faster than when running moderately; in other words, the cost of fuel will not increase with the speed, as in vessels propelled by steam.

Steamers of the same tonnage as the “Ericsson” never consume less than fifty tons in every twenty-four hours. The Atlantic steamers take in, for a winter voyage, twelve hundred tons. A vessel propelled by a caloric engine, of the same tonnage, at the same rate of speed-and unless Mr. Ericsson’s whole theory be fallacious, (which no one can believe who has seen what we saw on Tuesday,) there is no reason for doubting that by proportionately enlarging the cylinders, an equal if not greater speed can be obtained than any steamer has yet reached— such a vessel, we say, thus propelled, will require for a similar voyage not over 140 tons of coal, or about 1,000 tons less than a steamer of the same tonnage.

The Atlantic Steamship Companies estimate the coal for their steamers to cost them, adding the value of the space it occupies to the price of it, $25 per ton. That makes a difference at once in the expenses of the two vessels, resulting exclusively from the cost and transport of fuel, of $25,000 for a single passage.

This vast bulk of coal engrosses all the best freight room in the steamships, while Captain Ericsson can stow away his 140 tons in his coal bunkers beneath the freight deck, beside the engines, leaving all his freight deck entirely free, and of course productive.

In this connexion it is proper to state, that the immense weight of the coal required for the Atlantic steamers compels them to leave port always too deep in the water, anti to enter too light for their best running speed; while Mr. Ericsson’s ship is no more affected by the weight of the coal necessary for his engine, than an ordinary clipper is affected by the fuel which it carries for consumption in the cook’s galley.

There is also an important difference between the weight of the Ericsson’s engine and steam engines of equal power. The engine of the Ericsson weighs about 450 tons. The engines of our Atlantic steamers, including the water in the boilers, which of course becomes a part of the steamer’s burthen, weigh 1,000 tons.

The power of Ericsson’s engines is to be increased, not by raising the temperature in the furnaces, but by enlarging the cylinders, of which we shall speak presently. An enlargement of the cylinders of course would involve an increase of weight.

But this increase would not be considerable, as the power increases directly as the squares of the diameters of cylinders, so that by doubling their diameters the power is increased in compound proportion. But we need hardly say that this does not involve any proportionate increase of weight either to the cylinder or to the engine.

Now, we have shown that the motive power of one of the first class Atlantic steamers, at this season of the year:

  • Weighs: 1,200 + 1,000 = 2,200 tons.
  • That of the Ericsson propeller of the same class, at the outside: 800 tons.
  • Difference = 1,400 tons,

or, at the ordinary rates of freight in these steamers, an equivalent to more than $20,000. Add to this the cost of the extra coal, which, at $5 per ton, would amount to say $5,000, making an aggregate difference in the expense of the motive power of over $25,000 on each passage, independent entirely of the differences in the original cost of the machinery, and of its wear and tear and repairs, which, a slight inspect ion will be enough to satisfy any intelligent observer, must be in scarcely a less proportion favorable to the Ericsson patent.

Nor is the economy of this invention, for it is an invention, or a series of inventions, rather than a discovery, confined simply to the articles of fuel and machinery. It does not require anything like the number of firemen and engineers that swarm on steam vessels of a similar class. The “Ericsson” cannot find employment for more than one engineer, one fireman, and one coal trimmer, at a time. The engineer has little to do except to lubricate the bearings of the machinery, and the fireman to attend four double furnaces, which require but little more attention or trouble, and no more skill, than the ordinary house furnaces in our private dwellings.

On the other hand, the engineers, firemen, and coal trimmers of our first-class Atlantic steamers number over fifty persons, many of whom receive high rates of wages.

By this saving of help and equipage in directing the motive power, one of Ericsson’s ships may be fully manned by fewer persons, and of course at less expense, than one of our clipper ships of the same tonnage.

It is worthy of special notice that, as the cylinders are fed from the atmosphere, an opening is left all around them from the bottom of the ship to the upper deck, through which there is a constant circulation of fresh air down to the lowest depth of the engine room. From 50 to 70 tons weight of air are emptied into this great reservoir every hour, and we found it as cool, standing immediately beside the fires, as upon the main deck. In the summer this should naturally be the coolest part of the ship.

We have already intimated that the power of these engines depends upon the size of the cylinder. The original plan of the “Ericsson” contemplated a cylinder of sixteen feet diameter, but no founder would attempt to cast one so large, at the time the Ericsson’s machinery was building. The largest cylinder which it was then supposed could be made was one of fourteen feet diameter, and such a cylinder was accordingly furnished for the Ericsson, though only powerful enough for a ship of about two-thirds her tonnage.

The experience of Messrs. Hogg & Delamater, who cast these cylinders for the Ericsson, however, has satisfied them of the perfect practicability of casting a cylinder of twenty feet diameter, and we heard one of the firm state publicly, on Tuesday, that he would guarantie as many cylinders of those dimensions as he could have orders for.

That, of course, settles the question as to the practicability of multiplying the power of these engines indefinitely, and, of course, the speed of the vessels in which they may be placed. The “Ericsson,” with only about two-thirds the power which is clue to her tonnage, has made ten revolutions a minute, which is equivalent to ten miles an hour. No attempt has yet been made to ascertain the highest speed which she is capable of attaining with her present machinery. Nor would such an experiment reveal anything not already demonstrated by the simple fact that a vessel of two thousand toils burden has been propelled through the water by an engine which consumes but six tons of coal in twenty hours, at the rate of ten, or even nine, or eight miles an hour.

It is obvious to any man of ordinary understanding that the power, and of course tile speed, may be increased almost indefinitely by enlarging (lie cylinders. The formula of increase, Capt. Ericsson states, to be as the square of the diameter.

There are many other aspects of this wonderful invention which we should have been glad to present to our readers; we should also have been gratified with an opportunity of paying some more suitable tribute to the masterly genius who has worked out this great problem of mechanics, and to the sagacious, liberal-minded, and brave men who stood by him with their open purses during all his long struggle with the practical obstacles to the realization of his theory, which bristled along his path.

Some future time we hope to do our part in securing for them the honor which is their due. For the present, want of time and space both, compel us to leave the subject with the simple expression of our conviction, that the employment of heated air as a motive power by Capt. Ericsson, marks an era in the history of mechanism only less momentous and revolutionary than that which commenced with the first application of steam to a similar purpose.